Question 1

Which connective tissue layer directly surrounds each individual skeletal muscle fiber?

Accepted Answer

Endomysium

Question 2

In the structure of a sarcomere, which band contains only thick filaments and is located at the center of the A band?

Accepted Answer

H zone

Question 3

What is the primary function of the sarcoplasmic reticulum in skeletal muscle fibers?

Accepted Answer

Stores and releases calcium ions for muscle contraction

Question 4

During muscle contraction, which event occurs first at the neuromuscular junction?

Accepted Answer

Synaptic vesicles release acetylcholine into the synaptic cleft

Question 5

Which protein blocks the myosin binding sites on actin in a relaxed muscle?

Accepted Answer

Tropomyosin

Question 6

According to the sliding filament model, what provides the energy for the myosin head to return to its 'cocked' position?

Accepted Answer

ATP hydrolysis by ATPase

Question 7

Which equation represents the regeneration of ATP from ADP using creatine phosphate?

Accepted Answer

$$\mathrm{ADP} + \mathrm{Creatine\ Phosphate} \rightarrow \mathrm{ATP} + \mathrm{Creatine}$$

Question 8

During strenuous exercise, which process leads to the accumulation of lactic acid in muscle cells?

Accepted Answer

Anaerobic glycolysis in the cytoplasm

Question 9

Which pigment increases oxygen availability in muscle tissue for aerobic respiration?

Accepted Answer

Myoglobin

Question 10

A muscle fiber exposed to a series of high-frequency stimuli that prevents complete relaxation between twitches is experiencing:

Accepted Answer

Partial tetany

Question 11

Which equation best represents the net ATP yield from aerobic respiration of one glucose molecule?

Accepted Answer

$$\mathrm{Glucose} + 6\mathrm{O}_2 \rightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} + 28\mathrm{ATP}$$

Question 12

Which muscle fiber type is best suited for endurance activities and resists fatigue?

Accepted Answer

Slow fibers

Question 13

What is the minimum strength of stimulus required to generate an impulse through a muscle fiber and cause contraction called?

Accepted Answer

Threshold stimulus

Question 14

Which process describes the increase in the number of activated motor units within a muscle at higher intensities of stimulation?

Accepted Answer

Recruitment

Question 15

Which type of muscle contraction involves force generation without shortening of the muscle?

Accepted Answer

Isometric contraction

Question 16

Which event occurs during muscle relaxation after contraction?

Accepted Answer

Acetylcholine is rapidly decomposed by acetylcholinesterase

Question 17

Which muscle is responsible for flexion of the forearm at the elbow?

Accepted Answer

Biceps brachii

Question 18

What is the term for the continuous state of sustained contraction of a few motor units at a time within a muscle, even when at rest?

Accepted Answer

Muscle tone

Question 19

Which muscle group is responsible for extension of the knee?

Accepted Answer

Quadriceps femoris group

Question 20

Which muscle is involved in dorsiflexion of the foot?

Accepted Answer

Tibialis anterior

The Muscular System: Structure and Function

Study Guide - Practice Questions